Gunsight



March 19, 1957 os 2,785,465

GUNSIGHT Filed Nov. 50, 1953 2:1 E Gai dos Alnn INVENTOR.

United States Patent GUNSIGl-IT Alonzo F. Gaidos, Monrovia, Calif.

Application November 30, 1953, Serial No. 394,994

1 Claim. (CI. 33-56) This invention relates to manually adjustable gunsights preferably for use on revolvers and pistols and has for its object to provide an auxiliary rear sight readily attachable to the frame of the revolver directly behind the existing sight aperture.

Another object of the invention is to provide means for i bOth vertical and horizontal adjustment of the sight aperture, the vertical adjustment for distance and the horizontal adjustment to compensate for wind velocity elfect on the bullet in flight.

Still another object of this invention is to provide a graduated scale on the vertical adjustable member of the sight and a stationary indicating pointer adjacent the graduated scale so arranged that the pointer remains fixed on the fastening member of the sight, permitting the graduated scale member to be adjusted vertically without disturbing the position of the indicating pointer.

A further object of this invention is to provide a graduated horizontal bar for mounting the adjustable sight leaf, and provisions for micrometer control of the sight leaf in increments representing one (1) minute of angle.

Still a further object of the invention is to provide on the horizontal bar a sight leaf having a right-hand and left-hand indicating tab, the object of which will be explained later.

While rear sights for revolvers having both windage and elevation adjustments have been in use on revolvers and pistols for many years, such sights are only provided on the most expensive guns, as the guns are specially designed to provide for their mounting. However, the great majority of commercially available revolvers do not have adjustable rear sights. The conventional rear sight on a revolver is more or less an aiming groove or channel milled on the top of the frame directly above the ammunitioncarrying cylinder. For an adjustable rear sight for a revolver equipped only with a sighting groove, one would be required to add a sight on top of the frame considerably above the existing sight which, therefore, would also require modification or replacement of the front sight in order to compensate for the increased height of the rear sight.

My invention provides a means for attaching an adjustable rear sight to a revolver without the necessity to modify or replace the existing sights. It also provides for an auxiliary adjustable rear sight that can be readily attached to the revolver on the range for finer shooting and removed from the gun after leaving the range. The existing service sights on the gun will not be disturbed and will be ready at all times for use in ordinary shooting.

Other objects and advantages of the invention will become apparent from the following specification taken in connection with the accompanying drawings wherein Fig. 1 is a side view of a modern revolver of conventional type.

Fig. 2 is a side view of my adjustable auxiliary rear sight combining my invention.

Fig. 3 is a partial sectional rear view of my adjustable sight taken on line 3-3 of Fig. 2.

2,785,465 Patented Mar. 19, 1957 Fig. 4 is a top view of my rear sight showing the horizontal adjustable sight leaf mounted on the graduated bar.

Fig. 5 is a cross section of the sight taken on line 5-5 of Fig. 3.

Fig. 6 is a cross section of the stationary index pointer taken on line 6-6 of Fig. 2.

Fig. 7 is a perspective view of the sight bracket.

Fig. 8 is a perspective view of the micrometer screw.

Fig. 9 is a perspective view of the snap-type retainer ring for the micrometer screw.

A revolver such as previously described as applicable for use with my invention has a cover plate 2, over the compartment housing the lock mechanism of the revolver.

Plate 2 is secured to the frame 3 of the revolver with screws 4 and 5.

An adjustable rear sight which is readily attachable to revolver 1 is provided with a sight bracket consisting of a horizontal member 7 (Fig. 3) and a vertical member 8, an elongated slot 9 is provided in the vertical member to accommodate a screw 10 for fastening the sight to the frame 3 of a revolver 1. To attach the sight the screw 5 is removed from the side plate 2 and the sight is attached to the frame 3 with screw 10 which passes through a cylindrical hole 11 of indexing pointer 12. As screw 10 remains stationary after attaching the sight, tension on it will clamp the sight securely against the side plate 2 of frame 3 and loosening it will permit moving the vertical member 8 of bracket 6 up or down to the desired position on the scale 8a.

A cylindrical hole 13 is also provided in the vertical member 8 of bracket 6 and journaled therein is hub 14 of windage screw 15. A threaded extension 16 of the hub 14 is provided to actuate the adjustable sight leaf 27 in a manner to be described later. A plurality of detents 18 radiating from cylindrical hole 13 are formed in the face 19 of bracket member 6.

Cylindrical chambers 20 are diametrically disposed and formed in the head 21 of windage screw 15. Balls 22 are housed in the cylindrical chambers 20 and are at all times under bias of compression springs 23. The windage screw 15 assembled with balls 22 and compression springs 23 are retained in the bracket member 6 by means of a commercially attainable snap-type retainer ring 24, better illustrated in Fig. 9. The hub portion 14 of the windage screw 15 is provided with an undercut 25 to accommodate the snap-type retainer ring 24.

After securing the windage screw 15 containing balls 22 and compression springs 23 in the bracket member 6 by means of the snap-type retainer ring 24, it will be readily seen that rotating the windage screw 15 in either direction will result in an intermittent stop action as the balls 22 under bias of springs 23 fall into the detents 18 formed in the surface 19 of bracket member 9 as the balls become positioned directly opposite the detents 18.

The threaded portion 26 of the extension 16 contains a series of screw threads numbering eighty to the inch, the pitch of the screw, therefore, is .0125 inch. On the horizontal sight bar 7 of bracket member 6 is slidably-mounted a sight leaf 27 having an upright projection 28 containing a sighting aperture 29 formed therein. A depending projection 30 having screw threads 31 formed therein is provided to accommodate the threaded portion 26 of windage screw 15. The sight leaf 27 is also provided with indicating tabs 32 and 33 which serve two purposes; one, for retaining it slidably on the horizontal member 7 and the other to provide indicating pointers, the purpose of which will be described later.

The upper surface of horizontal member 7 is provided with a series of graduations 34 equally spaced and a cen ter zero index graduation 35. The space between each graduation measures .025 inch therefore, rotating the windage screw 15 in either direction two complete revolutions will move the slight leaf laterally across the horizontal member 7 a distance of one full space or .025 inch.

The commonly accepted mathematical formula for predetermining the point of impact of a bullet is to employ.

the minute of angle as a basis for moving the point of impact approximately one inch for each one hundred yards of shooting range. The tangent for one minute of angle equals .00029 inch per inch of base and since there are 3600 inches in 100 yards the tangent will equal for that distance 1.044 inches and for practical purposes the unit of one (1) inch is used in calculating windage adjustment on all commercial gunsights having windage correction features. Therefore, it Willbe readily seen that on a revolver having approximately 7.15 inches distance between sights as is the case when my auxiliary sight is attached to a revolver having a 6" barrel, the right triangle formed by the base line of 7.15 or line of sight and one graduation equaling .025" will produce an angle of twelve (12) minutes. Therefore, moving the sight aperture a distance of one graduation in either direction will have the effect of moving the point of impact 12 inches for each 100 yards of range. Since there are six interrupting stops produced in rotating windage screw 15 one revolution or 12 stops for two revolutions, the screw will move the sight leaf 27 a distance of .025 inch or equivalent of 12 minutes. Therefore, for each intermittent stop the sight leaf 27 will move the equivalent of one (1) minute of angle, thus affecting the point of impact 1.044 inches for each 100 yards of shooting range.

The sight leaf 27 when properly aligned with the axis of the revolver barrel is positioned on the horizontal member 7 of the bracket 6 so that the inside edges 32a and 33a of sight leaf 27 coincide with the second graduation mark on each side of graduated mark 35. This position is termed zero. Since the space between each graduation measures .025 inch, the space between edges 32a and 33a must therefore measure .100 inch. Therefore, zero position of the sight leaf 27, positions the sight aperture 29 directly in line with the axis of the revolver barrel. Theoretically, when the aperture 29, the front sight of the revolver and the target are in line, a shot fired from the gun should strike the target if adjusted to the proper elevation to compensate for effects of gravity on the bullet after leaving the barrel. However, the bullet in its flight might be aifected by air currents or a cross wind and even though the sights and target might be in line, the bullet will miss the target. If consecutive shots registering off the target prove-to be a uniform pattern the marksman needs to know only whether the shots are registering right or left of the target, and the number of inches the center of the grouping is from the center of the target. Assuming that the sight leaf is positioned at zero, a series of five aimed shots is .fired at 100 yards and the center of this group is found to be twelve inches off the target to the right, all the marksman need do is to move the inside edge 32a of indicating tab 32 to the next graduation nearer the zero line 35 and the point of impact of the next bullet fired should then register in the target.

A sight leaf having a double indicating pointer; one on each side of the zero line 35 will be found to be a distinct advantage to the marksman as it will greatly aid him to determine readily the proper setting of his sight if the shots are registering off the target. He needs only to learn this simple rule: That the center graduation 35 represents the target or zero, the right-hand indicating tab 32 represents bullet impact on right of target and the left hand indicating tab 33 represents bullet impact on left of target. Then, knowing the distance between center of target and point of impact right or left of the target, will enable him to make a quick mental calculation and affect the movement of the point of impact either right or left by simply rotating the windage screw 15 in the proper direction, i. e. clockwise if groups are registering to left of target and counter-clockwise if groups are registering to right of target. He does not need to look at the graduations on the sight bar 7 since he will feel distinctly each click of the interrupted stop as the windage screw 15'is being rotated. Each clic of course denoting l inch for every one hundred yards of shooting range. For example: If he wishes to move the point of impact twelve inches to the left, he will rotate the windage screw 15 counter-clockwise and count twelve distinct clicks. If, however, the target is only fifty yards away and the point of impact is still twelve inches to the left, he will rotate the windage screw 15 counter-clockwise and count twenty-four distinct clicks which should place the point of impact directly in the center of target.

An auxiliary adjustable gunsight having a sight leaf with two indicating pointers instead of one will be found to be a distinct advantage because it will in effect, virtually bracket (0) the target for the marksman, thus eliminating guess work. He can attach the auxiliary sight readily for use in competitive marksmanship qualification where a higher degree of shooting accuracy is necessary. Likewise, he can remove it after he leaves the shooting range without disturbing either his existing front sight or his service sight forming a part of the aiming groove on top of the frame.

It will be understood that the entire unit when manufactured will be as small and compact as to permit its placement directly behind the existing service sight which is an integral part of the gun. However, while certain features of the present invention are more or less specifically illustrated, I wish it understood that verio-us changes in form and proportion may be resorted to within the scope of the appended claim; similarly I wish it understood that the materials and finishes of the several component parts employed may -be such as the judgement and experience of the manufacturer may dictate or various uses demand.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

In combination with a firearm having a gunbarrel and front sight thereon, a gunsight of the character described comprising a sight bar having its longitudinal axis disposed substantially perpendicular to the longitudinal axis of said gunbarrel, spaced graduations on the upper surface of said sight bar including a zero graduation in direct alignment with said gunbarrel and said front sight, a channelshaped sight leaf fitting substantially about and slidingly engaging said sight bar with the direction of movement of said leaf being along the longitudinal axis of said bar, said sight leaf having one thereof extending vertically with respect to the upper surface of said sight bar and along one longitudinal edge of said bar, said end of said leaf having a notch on the upper edge thereof, the other end of said sight leaf terminating in a pair of spaced legs bent over the other longitudinal edge of said sight bar and engaging said upper surface of said bar, said legs having their opposing inner edges substantially perpendicular to the longitudinal axis of said bar so as to indicate the distance that said sight leaf has to be moved without respect to said zero graduation in order to have said notch in correct alignment with said front sight, and means to slideably move said sight leaf along said sight bar.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Aug. 28, 1908 

